1. Field of the Invention
The present invention relates to a fluidic device unit structure in which fluidic devices, such as valves and pressure switches, are integrated.
This application is based on Japanese Patent Application No. 2010-248390, the contents of which are incorporated herein by reference.
2. Description of Related Art
Conventional apparatuses that handle fluid, such as chemicals, are configured such that various constituent fluidic devices (valves, regulators various sensors, such as pressure sensors, various switches, such as pressure switches, etc) are connected by piping to form a single unit.
For example, in the case where a plurality of chemical fluidic devices are used, as in semiconductor manufacturing equipment, a structure that allows connection of chemical fluidic devices without using pipes has been proposed. Since no piping is needed, the entire system can be reduced in size.
Furthermore, it has been desired in recent years to develop a fluidic device unit structure in which a plurality of fluidic devices are integrated into a single unit for the purpose of, for example, reducing the footprint (projected area in plan view), which is effective in reducing the size of the apparatus because the component mounting space is reduced, reducing the number of leakage points, which is effective in improving the reliability of the apparatus and in simplifying the maintenance, and reducing the dead volume, which allows efficient use of the fluid.
Thus, a fluidic device unit structure in which a plurality of fluidic devices are integrated into a single unit to reduce the footprint has also been proposed (for example, refer to Japanese Unexamined Patent Application, Publication No. 2007-263356).
However, in the invention described in the above Japanese Unexamined Patent Application, Publication No. 2007-263356, since the various fluidic devices are fixed to a base member with bolts that are passed through through-holes formed in the fluidic devices and the base member, a diagonally extending channel is formed inside the fluidic device unit structure because of manufacturing and space limitations. Such a diagonal channel has the problem that a chemical solution flowing therethrough tends to stagnate, resulting in the possibility of causing so-called liquid pooling.
For example, there is the problem that a slurry chemical solution tends to solidify when it stagnates and may solidify in the liquid pooling described above.